Welding parameters
Current, voltage, wire feed speed, polarity and welding positions.
Welding parameters are the settings that decide how much heat goes into the joint and where it goes: welding current, arc voltage, travel speed, wire feed speed and electrode or wire diameter, plus stick-out, polarity and shielding gas flow. Together they set penetration, bead shape and heat input.
| Parameter | What it controls | Where to get the number |
|---|---|---|
| Current, A | Penetration, pool size, deposition | Current by electrode diameter |
| Arc voltage, V | Arc length, bead width, transfer mode | MIG/TIG settings chart |
| Wire feed speed, m/min | Current on a MIG/MAG machine | Wire feed speed calculator |
| Travel speed, mm/min | Bead size and heat input per millimetre | Heat input calculator |
| Position | How large a pool you can hold | Welding positions PA–PG |
Parameters are not independent knobs. Current sets penetration and pool size; voltage sets arc length and bead width; travel speed divides the energy over the length of the joint. Change one and the other two have to move with it, which is why "correct settings" always come as a set.
The position then rewrites all of them. In the flat position gravity holds the pool in the joint; in every other position it does not, so the pool has to be smaller — less current, a smaller electrode, and a technique that gives the metal time to freeze.
The arithmetic behind the settings lives in the calculators; this section is about what the numbers do.
- Joint preparation I, V, X, U and K preparations: the angle, root face and gap for each thickness, how the edge is cut and cleaned, and what too narrow a groove costs.
- The weld pool Weld pool meaning in one line: the metal molten under the arc right now. Its width, shine and edges tell you whether current, speed and angle are right, and what to change.
- Welding positions PA flat, PB/PC horizontal, PD/PE overhead, PF up, PG down: ISO 6947 chart with 1G–6G equivalents, current −15 % for vertical and −20 % overhead, what a test covers.
Frequently asked questions
Which parameter do I change first when the weld looks wrong?
Current, and by about 10 %. It has the largest effect on penetration and pool size, and the change is immediately visible in the bead. Only when the current is right does adjusting voltage and travel speed tell you anything useful.
What is the difference between PF and PG?
Direction. PF is vertical up: good penetration, slow, and what structural work means by "vertical". PG is vertical down: fast, shallow, and correct only on thin sheet and cellulosic root runs. Using PG where PF was specified is a reliable way to produce lack of fusion.